A popular topic on photography blog sites these days is someone posting about how the modern smart phones can now just about take the place of a full-frame camera and the phone camera photos are so good that most people can’t tell the difference anyway. Why bother with all those cumbersome camera bodies and lenses anymore? This always irritates me, and not just because I blew a bunch of dough on a full-frame camera and lenses, but because it just isn’t true in my opinion. But what’s my opinion worth anyway? So, I finally got irritated enough to see whether I had a point or was just being a sore-head and not giving modern phone cameras their proper due respect.

The smart phone

The smart phone I am using for this comparison is my personal phone, an iPhone 13 pro from last year. It has 3 cameras built-in, each with a 12MPsensor, to give you three different focal lengths as it doesn’t support changing lenses. There is a telephoto, wide, and ultra-wide giving you stated 35mm equivalent focal length and aperture options of 13mm f/1.8, 26mm f/1.5, and 77mm f/2.8. I’m not sure I buy those aperture numbers, but who knows. The iPhone also performs a great deal of automated post-processing on any picture you take to correct for short-comings of the built in camera.

The iPhone 13 Pro cost about $1200 last year, if I remember correctly. It has recently been replaced by the 14 Pro, but the camera should be about the same.

The full-frame camera

My camera is a Nikon Z 7II full-frame camera with a 45.7 MP sensor and for this comparison I am using the Nikon Nikkor Z 24-200mm f/4-6.3 VR lens. This lens is a medium quality lens and it provides the focal length of the main camera on the iPhone. The sensor on this camera is several times larger physically than the phone camera sensor and the lens should be much better so it should be no contest.

The full-frame camera can produce JPEG images that have a particular profile added to enhance them, but I have it configured to just give me a maximum resolution RAW image file that I will edit manually in Lightroom. A more cumbersome process than just having the phone make a finished image, but maybe I’ll get better results.

From Nikon’s website, the Z 7II currently goes for $2600 and the Z 24-200mm f/4-6.3 VR lens goes for $800. So, quite a bit of cost difference compared to the iPhone.

Comparisons

So, with my confirmation bias securely in place, I carried both of these devices with me on a recent hike at the wildlife refuge and took a few photos with each, trying to match the focal length and composition as closely as possible. The first photo was taken along the trail while there was still some sunlight left in the sky. A brightly lit scene tends to help hide the noise and imperfections of a camera as the sensor is working in its optimal signal quality range and the shutter is fast enough to reduce motion blur.

First is the iPhone camera photo. All settings and processing automated by the camera and out of my control.

Next the Z7II photo shot hand-held as with the iPhone photo. I did all the work with camera settings and editing. It took me a while to get the focal length correct so I had a bit less light on the little tree in the foreground.

When I look at these photos full size, I don’t think the iPhone photo looks terrible in comparison to the Z 7II photo, but the phone photo does look to me like it has had a lot of contrast and saturation applied, as well as noise reduction and heavy sharpening correction. If you look at the rocks in the iPhone photo you can see the results of the contrast and sharpening algorithm.

In the camera photo, there is zero contrast added, reduced highlights and boosted shadows, +12 vibrance, and +7 saturation as I was trying to match the iPhone photo. If I wanted to heavily adjust the texture, I could make the rocks look as harsh as in the phone photo. I made no noise correction or sharpening adjustments in Lightroom.

If I crop in on the little tree along the path, you can really see how the contrast and noise correction have kind of made a mess of it in the iPhone picture. There is clearly much poorer dynamic range and tree looks very harsh compared to the Z7II photo.

I would call this a victory for the full-frame camera though you might not immediately notice the difference unless you look. I think you would notice the difference quite a bit if printing the photos.

Next we have a photo of some stepping stones across a dry creek bed. The sun is behind the hills and everything is in shade. This provides a bit more challenging situation for the cameras as they need to increase the light sensitivity, which also increases noise sensitivity. First is the iPhone photo directly below. From the full photo you can see that the iPhone has really saturated the sky and put a lot of contrast in the stones of the creek bed to the expense of color information.

Next is the same scene shot with the Z 7II shown directly below. I tried to boost the saturation in the sky to match the iPhone photo above. You can see a lot more color depth in the Z 7II photo as is has much more dynamic range. The foliage is greener and the rocks in the creek bed show their natural color without the extreme contrast applied to them.

If I crop in on the stones, you can really see a difference. In my opinion the iPhone processing (left below) does some extreme work trying to correct for the dynamic range limitation and noise, and the result lacks color and shows blocky artifacts of extreme sharpening. The Z 7II photo (right) was shot at ISO1250 so I could hand-hold it, but even at elevated ISO, it has good color range performance. I did some noise correction in Lightroom as well, but it isn’t really much of a problem.

I think again, this shows what the iPhone is doing to correct for a small sensor with limited dynamic range, but there is only so much you can do with over-saturation, noise correction, and sharpening. This isn’t always as big a problem with good lighting conditions, but I don’t always shoot with good lighting conditions.

This next subject shoot actually surprised me quite a bit. In this scene we have a santa figure only lit by a Christmas tree. Very tough conditions for hand-holding a photo as there is very little light to work with. You either need a longer exposure, which is difficult hand-held or you need to boost the sensor gain, which results in increased noise in your photo.

Directly below is the photo shot on the iPhone. The iPhone actually does some amazing computational image stabilization while you are taking the photo and hand-holding the camera. I suppose they have put a lot of effort into this as people often take photos indoors under poor lighting conditions. The below is a pretty good photo.

Below is the same photo taken hand-held with the Z 7II. It was shot at ISO6400, which is quite high, in order to get a shutter speed that I could hand-hold (1/25th second) and even then I can see a little motion blur if I go looking. One thing the Z 7II does a lot better is capturing the light bulbs on the Christmas tree as they get mostly blown out on the iPhone. Also, you can’t see it because of the reduce resolution of my exports, but the textures in the iPhone photo get kind of harsh and crunchy as you zoom in.

Overall, I would have to call this one a draw though. This scene is quite a challenge for my lower cost lens and I’d much rather have a faster prime to let more light in and drop the ISO. The iPhone software did an amazing job in this circumstance.

Lastly, zoom. On the iPhone you get “digital zoom” which really means that it is cropping your image for you. With a full-frame camera and a zoom lens you get optical zoom, in which the lens reduces the angle of view and you get a “zoomed” image projected on the sensor instead of cropping part of the sensor. So, in this situation you would expect to lose a lot of resolution in the iPhone photo and you’d be correct.

In the photos below I have a zoomed in photo of a bird house taken from the same spot. The birdhouse was moving in the breeze so it changed positions between shots. The iPhone (right) was at 12x digital zoom and the lens on the Z 7II (left) was at 200mm.

You can tell the digitally zoomed photo (right) is lacking a lot of detail as it is cropped. The texture of the wood is a garbled mess and the image lacks color depth. Also, you can see that you don’t get the focus depth fall off that you get with an actual zoom (left). I have always considered the digital zoom to be a useless feature and I am still of that opinion.

My point with all of this was not (only) to make myself feel better about buying an expensive dedicated camera, but to demonstrate to myself that all of the articles that I seem to see in the photography blogosphere that argue that you can replace your camera with a smart-phone are ridiculous. The iPhone photos look fine, until you see them next to a similar photo taken by an actual camera. If you want snap shots of the kids or whatever scene to share on social media, the smart phone is fine for those low-resolution mediums. If you want photos of anything that you want to print or appreciate for years to come, there is still not substitute for a good dedicated camera.